Co-authored-by: Jan Beinke <git@janbeinke.com>

Co-authored-by: Jan Beinke <git@janbeinke.com>

Co-authored-by: Jan Beinke <git@janbeinke.com>

Co-authored-by: Jan Beinke <git@janbeinke.com>

Co-authored-by: Jan Beinke <git@janbeinke.com>

Co-authored-by: Jan Beinke <git@janbeinke.com>

Co-authored-by: Jan Beinke <git@janbeinke.com>

Co-authored-by: Jan Beinke <git@janbeinke.com>

Co-authored-by: Jan Beinke <git@janbeinke.com>

Co-authored-by: Jan Beinke <git@janbeinke.com>

Co-authored-by: Jan Beinke <git@janbeinke.com>

Due to the accepted "monad of no return" proposal, return becomes an
alias for pure. Return can be a pitfall for newcomers, so we decided to
use pure instead.

Both were lost while filtering the repository

All commits before this point are extracted from the `qd` repository.

The commits have been filtered to only include relevant files. I hope
this is a good compromise between squashing all history and having the
full history of another project attached to this repository.

This is a requirement for multi-hop network connections.